Added an extra sync token field for extra command buffer identification.

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 9b52768ac449f2392ed7edc95f653e8abffbb76e..4d5c3ca01b8b9f1cff4d54435beb28346e162376 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -5496,6 +5496,7 @@ void GLES2Implementation::GenSyncTokenCHROMIUM(GLuint64 fence_sync,
 
   // Copy the data over after setting the data to ensure alignment.
   SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
+                            gpu_control_->GetExtraCommandBufferData(),
                             gpu_control_->GetCommandBufferID(), fence_sync);
   sync_token_data.SetVerifyFlush();
   memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
@@ -5519,6 +5520,7 @@ void GLES2Implementation::GenUnverifiedSyncTokenCHROMIUM(GLuint64 fence_sync,
 
   // Copy the data over after setting the data to ensure alignment.
   SyncToken sync_token_data(gpu_control_->GetNamespaceID(),
+                            gpu_control_->GetExtraCommandBufferData(),
                             gpu_control_->GetCommandBufferID(), fence_sync);
   memcpy(sync_token, &sync_token_data, sizeof(sync_token_data));
 }